Dataset of fentanyl-containing methamphetamine and cocaine samples

Background: Increases in overdose deaths involving stimulants and opioids have raised the specter of widespread contamination of the stimulant supply with fentanyl. Media accounts of pervasive fentanyl contamination in all illicit drugs, including stimulants, have heightened concerns.Methods: We characterized the presence of fentanyl in methamphetamine and cocaine street drug samples sent to a mail-in drug checking service. Samples were collected anonymously from harm reduction program participants between May 2021 and March 2023, 92% collected in 2022 or later. Samples were analyzed using exactive gas chromatography-mass spectrometry (GCMS), with untargeted search. Sample donors provided information about expected drug and physical description.Results: Forty programs in 16 states submitted 973 samples from 58 counties, of which 347 were confirmed as methamphetamine (61%) or cocaine (38%) or both (1%) and included for analysis. Crystal methamphetamine rarely contained fentanyl (3/113), whereas 29% (28/97) of powder methamphetamine did. Powder methamphetamine was 11-times more likely to contain fentanyl (IRR 11.1; 95% CI: 3.4, 57; df 1, p